Adjust timing belt tension after installation

Hi, (1.9 TDI AVF, year 2002)

We replaced the timing belt this weekend, and everything went pretty well overall, aside from the minor mishaps that usually happen with this kind of DIY project. However, I still have a few questions.


1. Is it normal for the new belt to be quite tight on the gears?

2. After driving approximately 100 km, I checked the tension again. The belt is now slightly looser than when we initially tightened it; it's about 2 mm away from the mark on the tensioner pulley. Is this bad?

"3. Can I re-tension the belt while it's still installed, with the engine cold, without having to remove everything? Would I loosen the screws on the camshaft pulley, then the screws on the tensioner, and then adjust the tension?" With the belt in place, nothing should come loose, right?


This is the version of the tensioner.


Source: ahw-shop


Thank you very much, Sven.

Hello.

Quote:

1. Is it normal for the new belt to be quite tight on the gears?

If you assemble the belt along with the loosened non-drive (NW) wheel, and then install the idler pulley, it should go on without being too tight. Hopefully, they didn't choke on it.

Quote:

2. After approximately 100 km of driving, I checked the tension again. The belt is now slightly looser than when we initially tightened it; it's about 2 mm away from the mark on the tensioner pulley. Is this bad?

Actually, when driving, the engine warms up, and the voltage increases slightly. Still, that's probably okay. Maybe just turn the engine over manually a few times after tightening the chain. The voltage changes slightly when rotating due to the torque of the NW and ESP waves.

Quote:

3. Can I re-tension the belt while it's still installed, with the engine cold, without having to disassemble everything? Would I loosen the screws on the camshaft pulley, then the screws on the tensioner, and then readjust the tension? With the belt in place, nothing can get misaligned, right?

Tightening the lug nuts on a warm engine (20°-30°) without using a torque wrench. The left rear wheel remains stuck. After that, check the NW (network) and EZP (easy programming) settings again and adjust them if necessary.
Okay, I understand. Please provide the German text you would like me to translate into English. I will only provide the translation.
Herbert.

edit: please remove "ESP wave" and "EZP"! thanks, Michael.

Herbert wrote:

...and EZP...

AVF = 1.9 PD, longitudinally mounted with 131 hp.

Hello Herbert,

We didn't force it, but it was quite tight when inserting the intermediate roller.

We manually rotated the engine several times as instructed, and we also reinstalled the alignment tools, and everything was okay there.

Does the tightening torque really need to be adjusted when the engine is warm, or do manufacturers of pressure sensors (PD sensors) always explicitly state that the engine should be cold during installation/adjustment?
I thought the camshaft pulley should be loose so that I could only tension the belt on one side?


Thank you for the reply, Best regards, Sven.

scrdel wrote:

I thought the camshaft pulley might need to be loose so that I could only tension the belt on one side?

As soon as you release the camshaft sprocket without securing the camshaft, the camshaft will rotate uncontrollably! The valves ultimately exert pressure on the camshaft.

Okay, so: Either the complete program including setting all positions, or topping up the pressure without releasing the safety valve.

PS: As Herbert mentioned, 20-30°C is a cold engine temperature in the summer. So, don't get too hung up on the term "cold" when it comes to the PD (presumably referring to a specific device or system). Just because it's winter now, the belt doesn't necessarily need to be adjusted differently, and when it's time to replace it in the summer, no one will freeze the engine to be able to change the belt .

Greetings.
Guste.

Quote:

20-30°C, as indicated by Herbert, represents a cold engine in the summer.

And, above all, the temperature in the assembly hall at the factory .
hg
Herbert.

Hi, we tightened the belt again today.
You're right, I probably took the temperature issue a bit too seriously.

Thank you, Sven.